The development of the wireless communication standards for UTRAN (Universal Terrestrial Radio Access Network) and enhanced UTRAN (also called LTE—Long Term Evolution) in 3GPP (3rd Generation Partnership Program) is progressing and during this time the need for small home premise equipments, i.e., private radio base stations containing at least Radio Base Station functionality, typically for very small cells, so called femto cells or pico cells, has emerged.
A problem when introducing private radio base stations in a telecommunication system is that the transmission of common channels such as BCH in the telecommunication system will result in interference between adjacent cells of adjacent radio base stations as the number of nodes in the system may increase to a point where the management of the system will not be possible to plan and control for a network operator, such as by having explicit neighbour lists sent down from a cell as it is done in UTRAN today. Also, in systems where a home owner may own a radio base station for a very small cell, the management of the system will be not possible to plan and control for a network operator as home owners cannot be expected to perform the same complex network planning and configuration of the radio base stations as a network operator would do. Further, in current systems the cells that are neighbouring to a specific cell are explicitly signalled to the UEs to enable the UEs to find suitable cells to measure and use for mobility. In current networks there is a neighbour cell list (NCL) that could also define this. In a system with a high density of small cells, the list of neighbouring cells will become too large to handle and especially with many small cells with limited access rights the list have to be different for different UEs. It is therefore not feasible to identify the UE being close to a small base station by this means.
In GSM systems the Cordless Telephony System (CTS) system has been addressing the support for having small equipment for usage at home. However, the CTS-system has only one BCH transmission mode, i.e., the active mode.